The lib unit tests had gone stale (time values became newtypes) and no longer
compiled. Updated the test code to the current API and fixed the few real issues
the now-running tests surfaced.
Test-only:
- Wrap raw f64 time literals in Beats(...) where the API now takes Beats
(automation.rs); pass &TempoMap / Beats where signatures changed (clip.rs,
effect_layer.rs).
- shape.rs: assert the documented no-fill default (fill_color None) instead of Some.
- add_clip_instance / trim_clip_instances tests: register a vector clip with the
test's clip_id so the action's get_clip_duration lookup succeeds.
Production fix (delete_folder.rs):
- DeleteFolderAction(MoveToParent) reparented child subfolders to the deleted
folder's parent but never restored them on undo, orphaning them. Track the moved
subfolder ids and restore their parent on rollback.
Result: daw-backend lib 17 passed; lightningbeam-core lib 264 passed.
Skyler Lehmkuhl